Volumetric imaging by micro computed tomography: a suitable tool for wood identification of charcoal

The present study focuses on the application of state-of-the-art μCT, by using a sub-micrometre CT scanner as a tool for wood identification. Charcoal was chosen as a subject for this case study. The reason for choosing charcoal is based on economic as well as technical issues. Parallel to conventional wood anatomy, various promising approaches to identification are currently being developed worldwide in order to simplify the identification of processed wood. However, due to the carbonization process, such approaches are not applicable to charcoal. In view of the rapid development of μCT technology, it was decided to examine the extent to which wood anatomical studies can be supported and improved by modern μCT technology. About 17% of the annually harvested wood worldwide is converted to charcoal (FAO 2017), and the charcoal trade is one of the least controlled/monitored segments of the European timber market. Although charcoal has a significant market share of wood-based products, it is still not yet covered by any trade regulation, e.g. the European Timber Regulations (EUTR), (EU) No995/2010. For the present study, different wood types and the anatomical fine structural features were measured and displayed at different magnifications to visualize the performance of state-of-the-art μCT standards. Three different charcoal assortments were examined, and the results were checked against the given declarations of contents. The aim of this work is to evaluate the potential of the μCT technique in the field of wood identification and to assess its use for the regulatory control of charcoal and other wood products in the international timber trade. The results are encouraging and lead to the conclusion that the application of the μCT technique in the field of wood identification can be classified as very promising for the future.